Because the combination of these three hues produces white light, they are referred to as the main additive colors. They can be combined in any ratio. For example, red and green make purple; blue and yellow make orange; and all three colors combined make white light.
Cyan, magenta, and yellow are called the secondary colors. They are mixed from the additive primary colors using the rule that color mixing is simple: if one part red is added to three parts blue, you get cyan; three parts red and one part blue will give you magenta; and two parts red and four parts blue will make yellow.
The secondary colors are necessary for creating many other colors. For example, green can be made by combining equal amounts of cyan and magenta; blue by mixing equal amounts of cyan and yellow; and red by mixing equal amounts of magenta and yellow.
Finally, black can be created by mixing all of the colors together, including the secondary colors. This makes it possible to create a huge range of colors by combining the basic ones.
These are the only colors you need to know for art classes or when painting in general. If you want to go further, here are some more detailed explanations of how colors work together.
Red, green, and blue are the three additive primary colors. This means that practically all other colors may be made by additively combining the colors red, green, and blue in varied proportions, and white is formed when the three primaries are mixed together in equal amounts. For example, orange is 3/4 red and 1/4 green; yellow is 3/4 red and 1/4 blue; violet is 1/3 red and 2/3 blue.
In practice, color mixing using only these three primary colors is difficult because the results of such combinations are often not pleasing to the eye. For example, a red-green mix will usually appear pink instead of orange. A blue-yellow mix will usually appear grayish instead of gold. And a green-red mix will usually appear brown instead of black.
However, any one of these mixes can be used as a basis for further mixing with different colors. For example, if you wanted to make an orange color you could combine three quarters red with one quarter green and one quarter white; or you could use half red, half green, and half blue to make yellow. These new colors would be seen as distinct additions to the original three base colors--not replacements for them.
This process of adding colors from the palette to produce new colors is called blending. The more colors you blend together, the darker the resulting color will be.
The most widely utilized additive primary colors are red, green, and blue, and when all three are overlapping in an effectively equal mixing, white light is produced, as illustrated in the middle. The first two colors used by the Venetians for their palette were called rosa verde (green rose) and rosa blu (blue rose).
In 1854 William Henry Fox Talbot invented the photography process that has become known as collodion photography. This early form of photography was very difficult to use because it required extremely dark rooms and long exposure times of up to a minute per photo. It also required very sensitive paper coated with silver nitrate which could be damaged by even small amounts of light. In 1872 Joseph Swan developed the electric lamp which allowed for more convenient photography. He did this by adding chemicals to reduce the sensitivity of the paper to make it less likely to be damaged by light and then developing his photographs using chemicals which turned them black and white.
Talbot's invention was not the first photographic system, but it was the first one that worked well enough for practical use. Before this time photos had been taken using hand-powered apparatuses which were difficult to use and not particularly reliable, or using solar photography with films which required intense light sources and complicated development processes.
When these additive colors are blended, three more secondary colors are produced. These are as follows: (1) Cyan, (2) Magenta, and (3) Yellow.
Cyan is obtained by mixing red and blue. Magenta is obtained by mixing blue and yellow. Yellow is obtained by mixing red and green. Therefore, all secondary colors can be made by combining any two of the additive primary colors.
In fact, any color may be reproduced by combining two secondary colors. For example, brown can be made by combining magenta and cyan; gold can be made by combining yellow and red; dark blue can be made by combining black and blue; and white can be made by combining all three primaries - red, green, and blue.
The secondary colors are important because they show how to combine the primaries to make every color under the sun. Also, a large proportion of colors used in paints and dyes are derived from the secondary colors - violet, purple, pink, orange, red, brown, and gray.
Finally, although we usually think of light as being made up of only two colors - red and green - it is actually made up of a very large number of different wavelengths between red and green, which are called "colors".
White light is created by combining red, green, and blue light. The fundamental colors of light are defined as red, green, and blue (RGB). As depicted on the color wheel or circle on the right, mixing the colors creates new hues. This is a color that is added. It is called additive color theory.
New combinations of RGB colors are not limited to white. Any color can be made by combining different amounts of red, green, and blue. For example, magenta is used when more red than blue is needed, while cyan uses more blue than red. Monochromes are colors that are mixed from only one of the primaries—red, green, or blue.
The combination of red, green, and blue that makes white depends on how much of each color is being used. For example, if six tablespoons of red, five tablespoons of green, and two tablespoons of blue are combined, they make white with a color value of 22/100ths. The color chart below shows how many parts of each color need to be added to get various shades of white.
You can see from the table above that you can get almost any color you want by adding different amounts of red, green, and blue to white. However, there are limits to this method. For example, if you mix too much red or blue, the result will be outside the visible spectrum.